The scenario you describe is a bit wonky, in any case. They aren't going to make thousands of frivolous requests because the company actually hosting the email accounts has to comply with them and turn over the information. They're going to complain if they're getting bombarded with these requests.

Not to say it won't be abused at all--I'm sure it will be, as all such powers are--but this nightmare scenario of virtually everyone's emails being read for fun by federal agents is hyperbolic, to say the least.

University students do their sexy talk over phones, Skype, and Facebook, by the way, not university email accounts.